1. Field of the Invention
The ability to probe the chromosome, extra chromosomal genetic material, messenger, transfer and ribosomal RNA, to synthesize genetic material, as well as to manipulate genetic material, has increased the need for means to analyze the composition and base order of genetic material. It is therefore desirable to provide for recording various genetic fragments which allow for hybridization with the complementary fragment, so that mixtures may be analyzed for the presence or absence of a particular nucleotide sequence. In the development of a system for analyzing for particular nucleotide sequences, there are many considerations. The first consideration is the ability to separate a mixture into its constituent parts, based on molecular weight and/or electrophoretic mobility. The second consideration is the ability to accurately determine the nature of the constituent parts.
One method for determining whether a particular sequence exists is hybridization. That is, a particular nucleotide sequence is marked with a detectable label, conveniently a radioactive label, and is combined with the nucleotide sequence to be analyzed. If the two sequences hybridize so as to form a strong non-covalent interaction, it may then be reasonably assumed that the sequences are substantially identical. Various techniques for accurately determining whether hybridization has occurred and for qualitatively or quantitatively determining the amount of the nucleotide sequence have been developed. There is a continuing interest and need for improved and more accurate techniques for the rapid determination of the presence of a particular DNA sequence.
2. Brief Description of the Prior Art
Southern, J. Mol. Biol. 98, 503 (1975) teaches the transfer of DNA fragments from electrophoretically resolved DNA in agarose gels as single strands to strips of nitrocellulose. Noyes and Stark teach the transfer of DNA and resulting immobilization to diazobenzyloxymethylcellulose, Cell, 5, 301 (1975). Alwine et al, PNAS, USA 74, 5350 (1977) teaches the detection of specific RNA's in agarose gels by transfer to diazobenzyloxymethyl-paper and hybridization with DNA probes. Reiser et al, Biochem. Biophys. Res. Comm. 85, 1104 (1978) teaches the transfer of small DNA fragments from polyacrylamide gels to diazobenzyloxymethyl-paper and detection with DNA probes. Wetmur, Biopolymers, 14, 2517 (1975) teaches the use of dextran sulfate for renaturation of DNA. See also U.S. Pat. No. 4,139,346.